JP6405962B2 - Color difference limit sample creation method and color difference limit sample creation device - Google Patents

Description

  The present invention relates to a technique for creating a color difference limit sample indicating an allowable limit for variation in color difference.

  Conventionally, it has been common to use PCS values (PCS: Print Contrast Signal) when negotiating delivery standards for printed matter to be printed with a color printer, but there has been an increasing demand for color of printed matter. In response, recently, the use of color differences in the arrangement of delivery standards for printed matter to be printed by a color printer is increasing.

  An invention for managing the color difference of a printed material has already been disclosed. For example, in Japanese Patent Application Laid-Open No. 2003-260260, the allowable range of the color difference based on the color of the picture point in the print sample is quantified in a predetermined pattern point on the print sample. A displayed color sample display medium is disclosed.

  However, as in the invention of Patent Document 1, in order to numerically manage the color difference of the printed matter, not only an expensive measuring device (for example, a spectrophotometer) that can measure the color difference of the printed matter printed by the color printer is required. The workload of measuring the color difference of printed matter becomes a problem.

  When density is used for delivery standard arrangements, it is possible to check the quality of printed matter by measuring the density of printed matter printed by a color printer. However, it takes time to measure the density of multiple places on the printed matter. A density limit sample indicating the allowable limit is created, and the operator visually inspects the quality of the printed product by visually comparing the printed product with the density limit sample.

  Even when color difference is used as the delivery standard, it is only necessary to create a color difference limit sample that shows the allowable limit for color difference variation, and the operator can easily inspect the quality of the printed product by visually comparing the printed material with the color difference limit sample. However, since the color difference is the distance between two points in a three-dimensional color space with three directions, there are countless colors that have the same color difference with respect to the reference color. Only the color difference limit sample could be created.

JP 2011-230413 A

  Accordingly, an object of the present invention is to provide a method and apparatus that can automatically create a color difference limit sample. Note that Patent Document 1 also describes that a color difference limit sample of pattern points is attached to a color sample display medium, but there is no detailed description relating to the creation of the color difference limit sample.

A first invention for solving the above-described problem is an apparatus for printing a color difference limit sample when a color material used for printing a printed material is a color material C (Cyan), M (Magenta), or Y (Yellow). However, for each density fluctuation pattern that indicates a density fluctuation pattern that occurs in each color of CMY, the color difference that occurs at a specified point on the printed material when the density fluctuation of the pattern indicated by the density fluctuation pattern occurs is calculated. The process of checking whether the color difference falls within the color difference tolerance range is executed while changing the density fluctuation amount for the first time from the initial value of the density variation amount. step of searching a density change amount of immediately before the density change amount of color-difference boundary sample, the apparatus comprising for each of the density variation pattern, density variation of the pattern represented by the density variation pattern The printed matter when that occurred at a concentration variation for Kiirosa boundary samples are color difference boundary samples creation method characterized by performing the step of printing a color difference limit samples.
The density variation pattern includes a pattern in which the density of all three color materials changes in density in the direction of increasing and decreasing, and the density of one color material of the three color materials is increased. It is desirable that the pattern has a density variation in each direction and the direction in which the density is reduced, and a pattern in which the density of the two color materials of the three color materials varies in the density direction and in the direction in which the density decreases.

Furthermore, the second invention shows a pattern of density fluctuation occurring in each color of CMY when the color material used for printing the printed material is the color material C (Cyan), M (Magenta), and Y (Yellow). For each density variation pattern, a process for calculating a color difference occurring at a specified point on the printed material when a density variation of the pattern indicated by the density variation pattern occurs, and confirming whether the calculated color difference is within an allowable range of the color difference. By executing the density fluctuation amount for the first time from the initial value while changing the density fluctuation amount, the density fluctuation amount immediately before the color difference in at least one of the density fluctuation patterns falls outside the color difference tolerance range is used. after exploring the density variation amount, before SL for each concentration variation pattern, the concentration color difference boundary samples printed materials when produced in a concentration variation of the density variation in the pattern indicated by the variation pattern wherein the color difference boundary samples It is to chrominance criteria sample creating apparatus characterized by comprising means for printing.
The density variation pattern includes a pattern in which the density of all three color materials changes in density in the direction of increasing and decreasing, and the density of one color material of the three color materials is increased. It is desirable that the pattern has a density variation in each direction and the direction in which the density is reduced, and a pattern in which the density of the two color materials of the three color materials varies in the density direction and in the direction in which the density decreases.

  The density fluctuation amount immediately before the color difference in at least one density fluctuation pattern is outside the color difference tolerance range can be regarded as a density fluctuation amount that does not exceed the color difference tolerance. Since the printed matter when the change occurs can be used as the color difference limit sample, the color difference limit sample can be automatically created by the above-described invention.

The figure explaining the color difference limit sample preparation apparatus which concerns on this embodiment. The figure explaining the density fluctuation pattern used as the calculation object of a color difference. The figure explaining the creation method of a color difference limit sample.

  From here, preferred embodiments of the present invention will be described. The following description is not intended to limit the technical scope of the present invention, but is provided to aid understanding.

  FIG. 1 is a diagram illustrating a color difference limit sample creation device 1 according to the present embodiment. The color difference limit sample creation device 1 according to the present embodiment is a device realized using a color printer, and the control device 10 of the color difference limit sample creation device 1 according to the present embodiment has a method for creating a color difference limit sample. A computer program for implementation is implemented.

  There are four colors CMYK (Cyan, Magenta, Yellow, and Key Plate) used for printing the printed material, but there are three color materials CMY that affect the color of the printed material. A color printed on a printed material can be expressed by one point on a three-dimensional color space (for example, a LAB color space defined by CIE) having three directions corresponding to CMY. This is the distance between two points in space. Thus, since the color difference is a scalar value having no directionality, there are innumerable colors having the same color difference with respect to the reference color.

  Therefore, the color difference limit sample creation device 1 according to the present embodiment calculates the color difference generated at the designated point designated on the printed material when the density variation occurs, and whether the calculated color difference is within the allowable range of the color difference. By performing the process to check while changing the density fluctuation amount from the initial value for the first time, the density fluctuation amount that does not exceed the allowable range of color difference is searched, and the density fluctuation corresponding to the searched density fluctuation amount occurs. By printing the printed material as a color difference limit sample, a color difference limit sample can be automatically created.

FIG. 2 is a diagram for explaining a density variation pattern as a color difference calculation target. Since there are three color materials related to the color of the printed material, CMY, excluding K, the density variation pattern indicating the density variation occurring in each color of CMY can be expressed by three-dimensional coordinates having the respective directions of CMY. In FIG. 2, black circles are shown at positions corresponding to the density variation pattern that is a color difference calculation target. As can be seen from FIG. 2, in this embodiment, the density variation pattern in the direction of increasing the density and the density is lighter. Only the density fluctuation pattern in the direction is calculated as the color difference calculation target. This is because in actual printing, it cannot be assumed that the density of a certain color material varies in the direction of increasing and the density of another color material decreases in the direction of decreasing. Specifically, the density variation pattern in the direction of increasing the density and the density variation pattern in the direction of decreasing the density are the following 14 patterns.
-Total of two patterns in which the density of all three color materials (CMY) changes in density in the direction of increasing and decreasing direction-The density of one color material of three color materials (CMY) is increased A total of 6 patterns in which the density varies in each direction and the direction of lightening. • A total of 6 patterns in which the density of the two colorants of the three colorants (CMY) varies in the density direction and in the direction of lightening.

  FIG. 3 is a diagram for explaining a color difference limit sample creation method performed by the color difference limit sample creation device 1 according to the present embodiment. When printing a print sample, the color difference limit sample creation device 1 receives input data created in the CMYK mode. When printing the color difference limit sample, the color difference limit sample creating device 1 first converts the print data in the CMYK mode into the RGB mode, and displays an image of the printed material corresponding to the input data converted into the RGB mode on the display. Then, the operator selects a location on the printed material to be the designated point, and acquires information (for example, coordinate values) for identifying the designated point (S1).

  Next, the color difference limit sample creation device 1 according to the present embodiment sets a density variation amount that causes a density variation in the color of the designated point to an initial value (S2). The density fluctuation amount may be a density value, but the density fluctuation quantity is preferably a coefficient (for example, 1%).

Next, the color difference limit sample creation device 1 according to the present embodiment calculates the color of the designated point when the density variation occurs at the density variation amount at this time for each of the 14 density variation patterns described above (S3). ). The color of the designated point when density variations in density fluctuation amount when this occurs, depending on the concentration variation amount at this time becomes a value obtained by increasing or decreasing the value of the CMY color specified point. For example, when the color of the designated point is (C = 20, M = 40, Y = 60, K = 0) and the density fluctuation amount is 10%, the designation when the density fluctuation according to the density fluctuation amount occurs The following 14 colors are obtained as the color of the point.
+ 10% of all CMY colors: (C = 22, M = 44, Y = 66, K = 0)
The color which made -10% of all CMY: (C = 18, M = 36, Y = 44, K = 0)
Color with C only + 10%: (C = 22, M = 40, Y = 60, K = 0)
Color with C only -10%: (C = 18, M = 40, Y = 60, K = 0)
Color with M alone + 10%: (C = 20, M = 44, Y = 60, K = 0)
Color with M alone -10%: (C = 20, M = 36, Y = 60, K = 0)
+ 10% color for Y only: (C = 20, M = 40, Y = 66, K = 0)
Color with Y only -10%: (C = 20, M = 40, Y = 44, K = 0)
C + M + 10% color: (C = 22, M = 44, Y = 60, K = 0)
Color with C and M -10%: (C = 18, M = 36, Y = 60, K = 0)
C + Y + 10% color: (C = 22, M = 40, Y = 66, K = 0)
Color with C and Y -10%: (C = 18, M = 40, Y = 44, K = 0)
Color with M and Y + 10%: (C = 20, M = 44, Y = 66, K = 0)
Color with M and Y -10%: (C = 20, M = 36, Y = 44, K = 0)

Next, the color difference limit sample creation device 1 according to the present embodiment generates the color and density variation of the designated point when the density variation occurs at the density variation amount at this time for each of the 14 density variation patterns described above. The color difference from the color of the designated point when not present is calculated (S4). When calculating the color difference, an ICC profile describing the color characteristics of the color printer is used, and the color of the designated point defined by CMYK is converted into a value in the color space.

  Next, the color difference limit sample creation device 1 according to the present embodiment checks whether the color difference is within the allowable range of color differences in all density variation patterns (S5).

  The color difference limit sample creation device 1 according to the present embodiment changes the density variation amount so that the density variation becomes large if the color difference is within the allowable range of color differences in all density variation patterns (S8). The process returns to the process (S3) for calculating the color of the designated point when the fluctuation occurs.

The color difference limit sample creating apparatus 1 according to the present embodiment, in at least one of the density variation pattern, if out of the allowable range of the color difference chrominance, density variation for the color difference limit sample the concentration variation of this point For each density variation pattern , processing is performed to generate the submitted data as print data for the color difference limit sample when the density variation of the pattern indicated by the density variation pattern occurs with the density variation amount for the color difference limit sample , Print data for a color difference limit sample for each density variation pattern is created (S6).

  Next, the color difference limit sample creation device 1 according to the present embodiment prints a print sample using the submitted data in the CMYK mode, and uses the color difference limit sample print data created for each density variation pattern. A sample is printed (S7). Since the number of density variation patterns is 14, 14 color difference limit samples are printed.

At least density variation amount when the color difference is outside the allowable range of the color difference in one of the density variation pattern can be color difference is regarded as the concentration fluctuation amount not exceeding barely tolerance of the color difference, the concentration at this concentration variation The printed matter when the fluctuation occurs can be used as a color difference limit sample.

1 Color difference limit sample creation device 10 Color difference limit sample creation device control device

Claims (4)

When the color material used for printing the printed material is the three color materials C (Cyan), M (Magenta), and Y (Yellow), the device that prints the color difference limit sample shows the pattern of density fluctuation that occurs in each color of CMY. For each density variation pattern shown, calculate the color difference that occurs at the specified point on the printed matter when the density variation of the pattern indicated by the density variation pattern occurs, and check whether the calculated color difference is within the allowable range of the color difference. By executing the processing while changing the density fluctuation amount for the first time from the initial value, the density fluctuation amount immediately before the color difference in at least one of the density fluctuation patterns falls outside the color difference tolerance range is used for the color difference limit sample. step of searching a density variation, said apparatus, before Symbol each concentration variation pattern, density variation of the pattern represented by the density variation pattern occurs at a concentration variation for the color difference boundary samples How to create the color difference limit sample, which comprises performing the step of printing a color difference boundary samples of printed matter when.   The density variation pattern includes a pattern in which the density of all the three color materials changes in density and a direction in which the density of the color material decreases, and a direction in which the density of one of the three color materials increases. 2. The pattern according to claim 1, wherein the density variation pattern in each of the thinning directions and the density variation of the two coloring materials of the three coloring materials are a density variation pattern in each of the darkening direction and the thinning direction. To create a color difference limit sample. Color material 3 color material used for printing the printed material C (Cyan), M (Magenta ), when a Y (Yellow), for each concentration variation pattern indicating a pattern of density variation occurring to the colors of CMY, the concentration Calculates the color difference that occurs at the specified point on the printed material when the density variation of the pattern indicated by the variation pattern occurs, and checks whether the calculated color difference is within the allowable range of the color difference. For the first time, by executing while changing the density variation amount, after searching for the density variation amount immediately before the color difference in at least one of the density variation patterns is outside the allowable range of the color difference as the density variation amount for the color difference limit sample , before SL each concentration variation pattern, a means for printing a color difference boundary samples of printed matter when the concentration variation of the pattern indicated by the density variation pattern occurs at a concentration variation for the color difference boundary samples The color difference limit sample preparation apparatus according to claim that there were example. The density variation pattern includes a pattern in which the density of all the three color materials changes in density and a direction in which the density of the color material decreases, and a direction in which the density of one of the three color materials increases. 4. The pattern according to claim 3, wherein the density varies in each of the thinning directions, and the density of the two colorants of the three coloring materials varies in density in each of the increasing direction and the decreasing direction. Color difference limit sample making device.

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